New research could have major implications for understanding how bacteria and viruses interact

New research published in Nature could have major implications for our understanding of how bacteria and viruses interact says Professor Martha Clokie, Professor of Microbiology at the University’s Department of Genetics and Genome Biology.

The research is published today (Thursday 13 December) in this month’s issue of the journal by Sarah Kronheim from the University of Toronto and colleagues. The research identifies a new antiviral defence systems that can protect more than one bacterial species.

Professor Clokie, an expert in bacteriophage biology, was asked to submit a ‘News and views’ commentary piece to the journal about the research. She compared the bacterial defence system to being like a broad-spectrum insect repellent that humans might use to repel multiple types of pests. This contrasts with most known bacterial defence systems that just protect bacteria against one type of pest, so like humans only needing protection from Scottish midge flies.

The research is important in this field because it changes the way we understand how bacterium-attacking viruses (bacteriophages or phages) interact with bacteria. Scientists previously thought that bacterial defence mechanisms only protected individual bacterial cells against specific phages. They also thought they were based on proteins or RNA-protein complexes.

But this work points to a more broad-based defence where small molecules (known as metabolites) can defend different species of bacterium against numerous types of phages.

Professor Clokie explained: “The mechanism protects not just the cell that produces the anti-phage molecule, but also neighbouring bacteria cells of the same, and even different, bacterial species.”

This new work not only changes the way we think about how viruses and bacterium interact, but also opens up new and interesting questions that will be the focus of future research. This includes questions to address issues such as understanding how important these defence mechanisms are; if these defence mechanisms are continually produced or created only in response to phage infection; and to what extent these mechanisms can protect different bacterial species.

“How bacteria interact with phages is wonderfully sophisticated and unravelling it over the next few years is going to keep myself and lab (and others) busy but should help our being able to put phages to work in the context of developing new ways to treat antibiotic resistant bacteria.

“It was great to be asked to write this for Nature and to contextualise how important this is in terms of how we understand phage biology.”